Identify, on diagrams, the placenta and umbilical cord and describe their functions in relation to the exchange of dissolved nutrients, gases and excretory products between the blood of the mother and the blood of the fetus (structural details are not required)

Sourav PanNovember 3, 2024

Answered

The placenta and umbilical cord are essential structures that facilitate the exchange of nutrients, gases, and waste products between the mother and the developing fetus. Below is a description of their roles in this process, along with diagrams to illustrate their positions.

Diagrams

Placenta and Umbilical Cord Diagram:

Functions of the Placenta

1. Nutrient Exchange:
   • The placenta acts as a site for nutrient transfer from the mother to the fetus. Nutrients such as glucose, amino acids, and fatty acids pass from maternal blood into fetal circulation through the placenta.
2. Gas Exchange:
   • The placenta facilitates the exchange of gases. Oxygen from maternal blood diffuses into fetal blood, while carbon dioxide produced by the fetus diffuses back into maternal blood for removal.
3. Waste Removal:
   • Waste products produced by the fetus, such as urea and creatinine, are transferred from fetal blood to maternal blood via the placenta for excretion by the mother’s kidneys.
4. Hormonal Functions:
   • The placenta produces hormones such as human chorionic gonadotropin (hCG), estrogen, and progesterone, which are essential for maintaining pregnancy and supporting fetal development.
5. Immunological Protection:
   • The placenta provides a barrier that protects the fetus from some pathogens while allowing the transfer of maternal antibodies to help establish fetal immunity.

Functions of the Umbilical Cord

1. Blood Vessel Transport:
   • The umbilical cord contains two umbilical arteries and one umbilical vein. The arteries carry deoxygenated blood and waste products from the fetus back to the placenta, while the vein carries oxygenated, nutrient-rich blood from the placenta to the fetus.
2. Connection Between Fetus and Placenta:
   • The umbilical cord serves as a lifeline connecting the fetus to the placenta, ensuring that vital nutrients and oxygen are delivered efficiently while waste products are removed.
3. Facilitation of Movement:
   • The cord allows for some degree of movement within the amniotic sac, providing flexibility as the fetus grows and moves.